Identify patient characteristics which predict safety and efficacy of anticoagulation (AC) in the very old.

AC decreases stroke risk in patients with atrial fibrillation (AF) but remains underutilized in the elderly.  Time in therapeutic range (TTR) on warfarin correlates with safety and efficacy of AC.    There are no clear guidelines to identify patients >85 with AF who benefit most from AC.

Patients >85 years with AF treated with warfarin and managed by the Anticoagulation Services at Pen Bay Medical Center were prospectively enrolled.  Patients aged 70-85 matched by diagnosis, CHADsVASc score, and duration of AC served as controls.

Data collected at enrollment and every 6 months for 24 months: Fragility score, mini Cog, and mobility scale.  Primary outcome was TTR.  Secondary outcomes were all-cause mortality, stroke, and major bleeding events.

62 patients > 85 and 70 patients 70-85 years were followed, with a mean age of 91 in the older group and 77 in the younger.  The older group had a higher average fragility score (3.3 vs. 2.6, p=0.0002), lower mean mini Cog score (2.6 vs. 3.4, p=0.0019) and were less mobile (assistive device 54% vs. 27%, p=0.0002).  There was no difference in TTR between the two groups (70-85: 74.6%, >85: 76.3%, p=0.625).  All-cause mortality (27% vs. 11%, p=0.019), bleeding (10% vs. 6%, p=0.515), and stroke (6% vs. 0%, p=0.046) were increased in the older age group.

Therapeutic AC can be achieved as successfully in the very old as in younger patients, despite higher fragility scores, lower cognition, and worse mobility. Higher rates of mortality and stroke in the very elderly may be due to factors other than AC. Impairments in fragility, mobility, and cognition in the very old should not preclude AC.